The final whistle blew at midnight in Bonn on Thursday as UN officials set down to tot up a torrent of national plans, or “intended nationally determined contributions” (INDCs) in climate lingo.

They will be the building blocks of a new global warming pact to be finalised in Paris in December.

Switzerland kickstarted the process in February, while Argentina became the 146th and last country to meet a UN-imposed deadline.

Its climate change secretariat now has a month to produce a “synthesis report”, or giant INDC spreadsheet.

Independent assessments reveal that the pledges are insufficient to hold a temperature rise to the 2C internationally agreed goal. But they have lowered projected warming from 3.6C to 2.7C by the end of the century, according to Climate Action Tracker.

What have we learned in the process?

1. INDCs are an unruly lot

Baselines, business-as-usual forecasts, emissions-per-capita targets; as a collective, the pledges are messy and difficult to compare.

That was expected. Seeking to avoid the failure of Kyoto’s top-down approach, the UN didn’t set guidelines for what to include.

But trends have emerged. A country’s share of global emissions, renewable energy targets and adaptation plans figure in many submissions. Most set goals for 2025 and/or 2030.

Some have factored emissions for their entire economy, while others have excluded those from deforestation, or said they lacked reliable data.

Niger, Burundi, and Mozambique, some of the lowest scoring on the UN’s Human Development Index, played their part too.

3. Nor was size

A string of small island states added their voices to climate action, highlighting their vulnerability to rising seas.

The Marshall Islands’ 24 coral atolls are barely visible on a global map and account for 0.00% of world greenhouse gas emissions, according to EU data. Yet it targeted net zero emissions by 2050.

Samoa is on track for 100% of electricity generated by renewable energy and the Solomon Islands posted a 30% reduction in CO2 by 2030.

4. Oil-exporting nations were less keen

Just two of the Organization of Petroleum Exporting Countries (OPEC) delivered: Algeria and Ecuador.

Saudi Arabia, Nigeria and Iran are some of the biggest carbon polluters not to come forward.

Venezuela honoured remarks made to Climate Home in June that it recognised no deadline.

With support building for decarbonisation of the global economy this century, fossil fuels may have to stay in the ground, undermining the national interests of such countries.

Emissions curbs are a threat to oil-based economies (Pic: Shell/Flickr)

5. Tackling climate change doesn’t come cheap

Many developing countries put a price tag on their climate goals, taking the opportunity to signal finance demands to the rich world.

Those could fund carbon-cutting projects like solar farms, or measures to boost resilience to changing weather patterns like drought-resistant crops.

As of Honduras, one of the last dozen or so to pledge, these totalled more than a trillion dollars over the next 15 years, according to number crunching by Carbon Brief. India has since said it needs $2.5 trillion for its plan.

That will come from a mix of domestic and foreign sources. International aid budgets will be raided but the onus lays on the private sector to leverage the huge totals.

For now, countries are hotly contesting who will mobilise $100 billion a year from 2020 from rich to poor countries.

6. Then again, nor does reacting to its impacts

For many, climate change is no threat on the horizon. Several INDCs made that apparent in their quotations of damages from climate-linked disasters.

Floods in Bangladesh wrought damage over US$1 billion with 85,000 houses and millions of acres of crops destroyed in 2007, it said in its INDC.

Drinking water contaminated by surging waves and coastal erosion are frequent, Kiribati said, estimated to cost 35% of its GDP.

While Mozambique is losing US$0.6-1.2 billion a year in flood-damaged roads and crops sapped by droughts.